<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		
		
		<script>
			function nav () {
				console.log("navigator",navigator)
			}
			
		
		</script>
	
		
	</head>
	<body>
		<h3>请打开浏览器控制台，观察结果</h3>
			
	
		
				
		<button onclick="nav()">显示nav</button>
		
	
	</body>
</html>